The Indian Supreme Court has ruled in a landmark case that individual privacy is a fundamental right under the Constitution—a ruling that could threaten the future of the world’s largest biometric identification program. The case was over whether mandatory use of the national identity cards violated individuals’ privacy rights. The ID cards began as a voluntary program but then became required to receive social services, to open a bank account, to receive college scholarships and to access other government programs. The cards collect a slew of personal information and data. Activists say the Supreme Court ruling is a major victory for privacy rights in India.